initial commit

tlm/helpers.py

@@ -0,0 +1,61 @@
+import mailbox
+import email
+from email.policy import default
+from tqdm import tqdm
+import numpy as np
+
+
+def rolling_window(iterable, n):
+    """Passes a rolling window over the iterable, yielding each n-length tuple.
+    rolling_window(range(5), 3) -> (0, 1, 2), (1, 2, 3), (2, 3, 4)
+    """
+    it = iter(iterable)
+    try:
+        window = [next(it) for _ in range(n)]
+        while True:
+            yield tuple(window)
+            window = window[1:] + [next(it)]
+    except StopIteration:
+        return
+
+
+def read_mail_text(mbox_path):
+    """
+    Extract and concatenate all plaintext content from an mbox file.
+    """
+    texts = []
+    mbox = mailbox.mbox(
+        mbox_path,
+        factory=lambda f: email.message_from_binary_file(f, policy=default)
+    )
+    for msg in tqdm(mbox):
+        if msg.is_multipart():
+            for part in msg.walk():
+                if part.get_content_type() == "text/plain":
+                    try:
+                        text = part.get_content()
+                        if text:
+                            texts.append(text.strip())
+                    except Exception:
+                        pass
+        else:
+            if msg.get_content_type() == "text/plain":
+                try:
+                    text = msg.get_content()
+                    if text:
+                        texts.append(text.strip())
+                except Exception:
+                    pass
+    return "\n\n".join(texts)
+
+
+def join(tokens, punctuation=".,?!:;'\""):
+    "Joins text, but does not give extra space before punctuation."
+    tokens = [t if t in punctuation else ' ' + t for t in tokens]
+    return ''.join(tokens).strip()
+
+
+def softmax(x):
+    "Convert a vector of scores (logits) into a probability distribution."
+    e = np.exp(x - x.max())
+    return e / e.sum()